Shock wave actuated photoflash bomb



July 15, 1952 R. G. CLARKE ET AL 2,603,155

SHOCK WAVE ACTUATED PHOTFLASH BOMB Filed June 12, 1947 Patented July 15, 1952 UNITED;

2,603,155 sHocx WAVE AcTUATEn rno'rorLAsn e 1 BOMB Richard G. Clarke, Suffield, `Conn.,- Henry Gn Derbyshire, Binghamton, N. Y., and lfarryn-S.v Edwards, Evanston, and Ferdinand. J. Shore. Champaign, Ill., assignors to the United States vof America as Irepresented by the Secretary oi' Application .rune 12, 1947, sei-iai navegaba f 2. claims. (ci. 1ozccf This invention relates toa photoflash bomb useful for military and other purposes, in which the hash is generated by the shock wave of a high explosive acting upon a volume of gas carried by the bomb. The term bomb or shell includes projectiles, flares and torpedoes.

One object of the invention is to provide a device of this character :for photographic use. The extremely short but brilliant ash generated has less tendency to produce blurred pictures than those taken with metal-oxidant-using devices. Metal-oxidant systems give flashes many times as long as are produced by the present invention.

Another object is to provide a system in which the color of the flash may be predetermined within limits, while obtaining the extreme shortness of ash just mentioned.

Another object is to provide a photoflash bomb which may be detonated at a selected time, thus providing the flash when the bomb is in a preselected position in relation to the camera.

Another object is to provide a photoash bomb or shell that will not become unsafe due to leakage therein of moisture. It is well known that metal-oxidant compositions, if they become moist, tend to initiate spontaneous chemical oxidation reactions which may become explosive.

In the drawing, I is the metallic body of the bomb or projectile. I I are driving bands for use when the assembled device is to be shot from a piece of ordnance. I2 is a lling of high explosive, for example, trinitrololuene or shell penta-nitro-erythrol. At the base I3 of the bomb is a detonator I4 which is preferably radio-controlled. Such radio-control may be of the conventional proximity-fuse type or it may be a radio remote control, also of conventional type. The after part I5 of the bomb may be shaped to .give the desired night characteristics. While a conventional boat-tail shaped projectile is here shown, the shape may be varied to suit requirements.

Attached to the front of the body I0 by any desired means such as threads I6, there is a glass or transparent plastic nose I1. Within the nose Il, which may and preferably is hermetically sealed, there is a filling I8 of a gas, the molecule of which contains not more than two atoms. Argon, hydrogen, helium, krypton, neon and xenon or air are examples of such gases. As high a molecular weight as possible is preferred provided that the molecule contains not more than two atoms, but preferably contains only one. The gases mentioned, will, in their excited states re- 2 sulting from, an explosive shock wave, radiate light of. the vsame colors which they radiate when exposed to electrical discharge.- The volume of light is much greater, however.y Bomb samples weighing from 1/2 to 1 pound produced an estimated 400 106 peak candlepower lasting for not more than 10-4 second when air was used. Argon is however the preferred gas. It seems evident therefore, that smaller bombs may be able to do the work that requires much larger conventional bombs at present. Argon is believed to produce twice as much light as air when subjected to identical high-explosive shocks. y

In order to enhance the photoash effect by creating a higher explosive pressure on the gas IS, it is preferred to use the explosive charge I2 in the form of a hollow cone at its forward end. Such construction enables the Well-known Munroe effect to be obtained. In order that the charge I2 may be poured or cast into this preferred form, a second gas container I9 which is conical and which contains a second gas lling I8, preferably of the same gas as the nose charge I8, is employed. It is provided with a harige 2e which is held between the nose I1 and the body I5. The fiange 20 is a continuation of a seal 2l which is employed if the second gas charge I8 is to be hermetically sealed within the cone IS. Such construction is preferred. In this Way both a larger gas volume and a higher explosive pressure, leading to a more brilliant ilash, are ob tained.

While the prior art shows blasting gelatin packed in a container in which there is nitrogen, argon or helium, it would be impossible thereby to utilize the effect which we obtain, assuming that the prior art unwittingly obtained it.

A process of photography is involved in our invention. For night photography, we set up the camera, focus it upon the object We wish to photograph, open the shutter in substantially total darkness or behind the protection of a lter, shoot the bomb of our invention toward or over the target and detonate the bomb by proximity fuse action or remote radio control to illuminate the target. After the effect has registered on the photographic film or plate, we close the shutter or have it closed automatically.

The invention claimed is:

l.. A photoflash bomb or shell comprising a body, a fuze in the base of said body, a filling of high explosive in said body in contact with said fuze, said high explosive filling having at its forward end a conical depression centered on its longitudinal axis, and in said depression a transhigh explosive in said body in contact with said Y fuze, said high explosive lling having at its forward lend a conical depression centered on its longitudinal axis, a transparent container hermetically containing a substantial volume of argon gas in said conical depression and a nose for said bomb or shell comprising a transparent container attached to the said bomb or shell body, said container hermetically enclosing a substantial volume of argon gas.

RICHARD G. CLARKE. HENRY G. DERBYSHIRE. HARRY S. EDWARDS. FERDINAND J. SHORE.

REFERENCES CITED The following references are of record in the file of this patent:

4 UNITED STATES PATENTS Number Number Name Date s Down I V V ,Aug.18, 1914 Fulcher -4 Deel2, 1924 Fairchild et a1. June 9, 1925 Hammond Apr. 5, 1927 Gardner Apr. 14, 1936 Greenlee Jan. 6, 1942 Gray Sept. 9, 1947 Page May 4, 1948 FOREIGN PATENTS Country Date vFrance Jan. 4, 1939 Great Britain Nov. 6, 1945 OTHER REFERENCES The Shaped Charge by Iarrey, an article in the Explosives Engineer, July-August 1945, pages 

1. A PHOTOFLASH BOMB OR SHELL COMPRISING A BODY,L A FUZE IN THE BASE OF SAID BODY, A FILLING OF HIGH EXPLOSIVE IN SAID BODY IN CONTACT WITH SAID FUZE, SAID HIGH EXPLOSIVE FILLING HAVING AT ITS FORWARD END A CONICAL DEPRESSION CENTERED ON ITS LONGITUDINAL AXIS, AND IN SAID DEPRESSION A TRANSPARENT CONTAINER HERMETICALLY CONTAINING A SUBSTANTIAL VOLUME OF ARGON GAS, SAID CONTAINER BEING ATTACHED TO THE SAID BOMB BODY. 